21115053541 has 6 divisors (see below), whose sum is σ = 22430178290. Its totient is φ = 19872991296.

The previous prime is 21115053527. The next prime is 21115053563. The reversal of 21115053541 is 14535051112.

It can be written as a sum of positive squares in 3 ways, for example, as 5423733316 + 15691320225 = 73646^2 + 125265^2 .

It is not a de Polignac number, because 21115053541 - 2⁷ = 21115053413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115053511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36530946 + ... + 36531523.

Almost surely, 2^21115053541 is an apocalyptic number.

It is an amenable number.

21115053541 is a deficient number, since it is larger than the sum of its proper divisors (1315124749).

21115053541 is an equidigital number, since it uses as much as digits as its factorization.

21115053541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73062503 (or 73062486 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 28.

The spelling of 21115053541 in words is "twenty-one billion, one hundred fifteen million, fifty-three thousand, five hundred forty-one".